The invention relates to a dispenser for dispensing pharmaceutical liquids. Such a dispenser comprises a housing, a liquid reservoir arranged within the housing, an exit opening through which the liquid can be discharged into a surrounding atmosphere, an outlet channel connecting the liquid reservoir to the exit opening, and an outlet valve. The outlet valve can be opened in a pressure-dependent manner or can be actuated manually, and is arranged in the outlet channel and, with the outlet valve closed, subdivides the outlet channel into a first portion upstream of the outlet valve and a second portion downstream of the outlet valve.
Dispensers of the type in question are known in general from the prior art. They have a liquid reservoir, from which liquid can be delivered in the direction of the exit opening, it being possible for this to take place via a large number of different mechanisms. It is thus possible for the liquid reservoir to be designed in the form of a squeezy bottle, of which the contents can be subjected to pressure as a result of the walls being deformed. It is also possible to use a separate pumping device. Dispensers of the type in question have an outlet valve. This is a valve which is arranged in the path of the liquid immediately upstream of the outlet opening. It is usually an outlet valve which can be opened in a pressure-dependent manner, the valve being opened as a result of the liquid in the liquid reservoir, or a sub-quantity removed therefrom, being subjected to pressure and closing automatically again as soon as the corresponding positive pressure in relation to the surroundings is done away with. However, it is also possible here, in principle, to use other types of valves. It is thus possible, for example, to provide for the liquid in the liquid reservoir to be subjected to permanent pressure and for the dispenser to be handled using a handle which can be actuated manually to open the outlet valve.
In the dispenser of the type in question, the outlet valve, once closed, does not allow any liquid which has passed into the second portion of the outlet channel, or which has remained in the environment of the exit opening outside the outlet channel, to be taken back into the dispenser. This prevents any possible contamination of the contents of the liquid reservoir as a result of liquid residues being taken back in.
The residual liquid therefore remains in a region which is accessible from the outside. However, there is a risk of contamination here.
In order to avoid contamination in particular in the case of preservative-free liquids, it is already known, in principle, from the prior art for the dispenser to be provided with antibacterial surfaces which come into contact with the liquid. A description is given of this, for example, in U.S. Pat. No. 5,232,687, of which the exemplary embodiment describes a dispenser which has an outlet valve of antibacterial design.
It has been found in the past, however, that configuring surfaces with antibacterial qualities may also have problematic secondary effects. Depending on the ways and means of configuring the antibacterial surfaces, it should be noted that constituent parts of the correspondingly designed surface detach from the latter and pass into the liquid. They are then dispensed together with the liquid. This is disadvantageous from a medical point of view.